Sir Bradley Wiggins last week pulled out of the Giro d’Italia cycle race, which he had hoped to win, with a chest infection. Such a mischance could afflict any athlete, but his lacklustre showing inevitably brought back memories of the gold medal and Tour de France victory that sealed a triumphant point in British history. Sir Bradley’s year of glory was also ours.

Think back to the Olympics, in which many of Britain’s athletes proved themselves the best in the world and volunteers worked selflessly to help their fellow citizens. Remember the Queen’s Diamond Jubilee, when hundreds of thousands lined the streets of London to honour our past and celebrate our future. It seems almost incredible to think that, less than a year ago, this was a nation high on hope and generosity.

The Britain of 2013 seems another country. The Conservative Party, the self-proclaimed curator of our heritage, is in disarray if not in ruins after a schism over the EU and David Cameron’s pyrrhic victory on same-sex marriage. He may think, and he would be right to do so, that he is on the side of history. His fatal error has been in failing to persuade his loyalists that he is also on their side.

Being begged to rescue the PM, as Ed Miliband was on gay marriage, is the gift of which Opposition leaders dream. Satisfaction in the Miliband camp was tempered, however, by the Labour Party’s defiance of Isaac Newton’s third law of motion. In politics, as in science, symmetry decrees that if something moves forward, then something else must move back and vice versa. Yet opinion polls are consistently showing that, for all the Tory party’s agony, Labour is also leaching support.

The soft double-digit lead that Mr Miliband once enjoyed has withered, with two recent polls putting the party on 35 points. Nor can the slender advantage over the Tories be relied on. As one senior figure says, if growth recovers even slightly, then the Conservatives will benefit while, in a general election, “Ukip support will flake to the Tories”.

There is a bewilderment at the top of the party that the Opposition is so impotent against the “kamikaze” Tories, whose disasters have far exceeded Labour’s expectations. A Conservative hierarchy that is said to regard its own activists as “swivel-eyed loons” and which characterises swathes of voters as lazy, bigoted or scroungers can hardly be surprised if that dislike is reciprocated in spades.

The question is why the emollient Mr Miliband is also the beneficiary of this toxic mood. “It’s 10 years since anyone slammed a door in my face, but it’s happened twice in the past few weeks,” says one of his party’s most popular campaigners. “The disconnect from politics is a curse on everyone.”

According to one influential player, Labour is run by elitists who think that “the voters are the problem”. Party polling is said to show that the angry and forgotten are the paradox people: “Pro-European but anti-EU, pro-worker but anti-union, pro-compassion but anti-welfare, pro-marriage not anti-gay.” As one analyst puts it: “It would be graceful if the party at least listened kindly to people rather than interrupting or ignoring them.”

Since Mr Miliband is not going to tack Right, he must find some other means of allaying fears not only in the country but among a shadow cabinet that is staring, for the first time in many months, at the spectre of defeat. Influential figures who have kept their counsel until now are saying openly that there is only one way for Labour to win back trust.

Labour, Mr Miliband is being told, must explain precisely what its spending plans entail. Waiting until much nearer the election, as Ed Balls wishes, is no longer seen as an option. Instead the Labour leader is being urged, directly or through relayed murmurings, to use next month’s spending review to give details of extra expenditure in his first months of office and the measures he would take to bring down the deficit over the longer term. As well as arguing for extra spending on housing and jobs, some senior figures are hoping to prevail on the leader to dump the VAT cut championed by Mr Balls on the grounds that it no longer fits the Labour message.

That credo, Mr Miliband is being told, will never be heard unless Labour immediately dispels the charge that it cannot be trusted with the economy. “We can no longer say we don’t know,” says a senior figure who believes that Labour can only make its pitch on difficult issues, such as child care and social care, when it has been clear on deficit reduction. Should Labour fail to act, then George Osborne will set the terms of the debate. As one leading activist says, “I don’t mind going over the top of the trenches to fight the Tories on what we believe in, but we risk being trapped in the trenches they have built.”

Dribbling out individual initiatives will do nothing to assuage a nation so damaged by alienation that, as one Miliband backer says, “no policy pill will make things better”. Instead, Britain cries out for direction.

Great leaders are, without exception, optimists. Abraham Lincoln, who appealed to “the better angels of our nature”, abolished slavery against opposition that made Tory backbenchers look like the Sisters of Mercy. Margaret Thatcher, Tony Blair and Barack Obama drew voters from across political divides who believed, however fleetingly, that each could change the character of a nation for the better.

Mr Cameron now faces the doleful charge that he is altering Britain for the worse. His huskies and windmills could have been more than just the props of the dilettante moderniser, for the PM is indeed a social liberal who sought to change the “nasty Party”. Instead, Mr Cameron has achieved the considerable feat of turning Britain into something that could be mistaken for a nasty country.

Britons’ attitudes are hardening towards the poor not through malevolence but because of anxiety and a pessimism exacerbated by politicians who fail to say that Britain remains a great nation that can be greater still. Crime is at a 30-year low, the collapse of manufacturing has been greatly overstated, and welfare goes primarily to old people, not “shirkers”, with the lion’s share of 52 per cent spent on pensions. Even elitism is on the wane. Oxbridge alumni comprised 62 per cent of the top government and Civil Service jobs in 1974; by 2007 that had fallen to 42 per cent.

No one wants a Pollyanna Party when hardship is so prevalent. As David Stuckler says in his new book on the consequences of economic theory, austerity would never have passed a clinical trial. With suicides rising and suffering rife, voters who rallied behind the Olympics are desperate for reasons to be hopeful.

“Without knowledge of wind and current, without some sense of purpose, men and societies do not keep afloat for long.” As the tide turns against the Tories, Labour strategists should heed the words of the social thinker, Richard Titmuss.

Admiral Miliband cannot be sure of avoiding shipwreck unless he tells voters what course, exactly, he is steering.